hdu 4001 动态规划

比赛的时候，俊祥一说题目，我就马上意识到是动规，当时我正打着那道悲剧的题目，就让海峰打了，他二十来分钟吧就打完，而且一遍就过了。昨天晚上我再打这题，打了四十分钟，还WA了好几次才过。海峰真是强啊，佩服佩服！

/*
 * hdu4001/linux.cpp
 * Created on: 2011-9-5
 * Author    : ben
 */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;

typedef struct {
    int a;
    int b;
    int c;
    int d;
} Block;
typedef long long I64;
const int MAXN = 1010;
Block block[MAXN];
I64 dp[MAXN], N;

bool operator<(const Block &b1, const Block &b2) {
    if (b1.a != b2.a) {
        return b1.a < b2.a;
    }
    if (b1.b != b2.b) {
        return b1.b < b2.b;
    }
    return b1.d > b2.d;
}

inline bool judge(const Block &b1, const Block &b2) {
    if (b2.a < b1.a || b2.b < b1.b) {
        return false;
    }
    if (b2.a > b1.a && b2.b > b1.b) {
        return true;
    }
    if (b2.d == 0) {
        return true;
    }
    if (b2.d == 1) {
        return (I64) b2.a * b2.b > (I64) b1.a * b1.b;
    }
    return false;
}

void work();
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    work();
    return 0;
}

void work() {
    int n, temp;
    I64 ans;
    while (scanf("%d", &n) == 1 && n > 0) {
        for (int i = 0; i < n; i++) {
            scanf("%d%d%d%d", &block[i].a, &block[i].b, &block[i].c,
                    &block[i].d);
            if (block[i].a < block[i].b) {
                temp = block[i].a;
                block[i].a = block[i].b;
                block[i].b = temp;
            }
        }
        sort(block, block + n);
        memset(dp, 0, sizeof(dp));
        for (int i = 1; i <= n; i++) {
            dp[i] = block[i - 1].c;
            for (int j = i - 1; j > 0; j--) {
                if (judge(block[j - 1], block[i - 1])) {
                    if (dp[j] + block[i - 1].c > dp[i]) {
                        dp[i] = dp[j] + block[i - 1].c;
                    }
                }
            }
        }
        ans = -0x7fffffff;
        for (int i = 1; i <= n; i++) {
            if (dp[i] > ans) {
                ans = dp[i];
            }
        }
        printf("%I64d\n", ans);
    }
}